Hypodermic needle supporting hub



HYPODERMIC NEEDLE SUPPORTING HUB Filed May 29, 1969 2 Sheets-Sheet J I INVENTOR 74400;; 5744/0219: fm awz ATTORNEYS April 21, 1970 T. s. SENKOWSKI HYPODERMIC NEEDLE SUPPORTING HUB 7 2 Sheets-Sheet 2 Filed May 29, 1969 INVENTOR 2 /409505 STHIVISLIFIJS J'EA/(Alfltk/ ATTORNEYS United States Patent O 3,507,279 HYPODERMIC NEEDLE SUPPORTING HUB Thaddeus Stanislaus Senkowski, Cedar Grove, N.J., as-

signor to Becton, Dickinson & Company, East Rutherford, N.J., a corporation of New Jersey Continuation-impart of application Ser. No. 600,135,

Dec. 8, 1966. This application May 29, 1969, Ser.

Int. Cl. A61m /26 U.S.' Cl. 128-221 4 Claims ABSTRACT OF THE DISCLOSURE An improved cannula supporting hub is provided with a tubular body portion and a pair of radially outwardly extending diametrically opposed flanges. The bottom surface of each flange is longitudinally spaced a small distance from one end of the body portion and the bottom of each flange is beveled from the body portion junction to the flange free edge. The top surface of each flange is tapered for the major portion of its arcuate length to define a partial thread which cooperates with the Luer adapter of the hypodermic syringe with which the hub is to be associated in securing the hub to the syringe.

CROSS REFERENCE TO OTHER APPLICATIONS The present application forms a continuation-in-part of patent application S.N. 600,135 filed Dec. 8, 1966 for a Hypodermic Needle Assembly now abandoned.

BACKGROUND OF THE INVENTION Disposable hypodermic syringes are enjoying widespread use and increased popularity. In many instances, it is necesary that the disposable syringe be provided with a detachable cannula, and in this connection, the syringe may be provided with a Luer-type retaining collar for receiving and securing the cannula.

The typical prior art needle hub for a disposable hypodermic syringe, such as that which is discussed in the co-pending application of Joseph T. Welch and myself for an Improved Hypodermic Assembly and Method of Mak ing the Same, S.N. 455,548 filed May 13, 1965, now Patent No. 3,402,713, issued on Sept. 24, 1968, is constructed of a relatively rigid thermoplastic material such as styrene. The relatively rigid hub may be maintained in a mating reationship with the Luer adapter by the application of frictional compressive forces at the points of contact of the Luer adapter and hub, namely, along the sides of the hub flanges.

Attempts to use less rigid materials, such as polypropylene, have met with only a limited degree of success, because such materials had insuflicient torque capacity to provide an adequate seal between the mating parts of the Luer adapter. Such hubs also have a tendency to work loose from the Luer attachment during handling because of the inability of these relatively weak materials to withstand the axially applied load to which they are subjected during use.

SUMMARY OF THE INVENTION It is, therefore the principal object of the present invention to provide a plastic hub for disposable needles which can be manufactured of materials having relatively low moduli of elasticity, but which will still provide adequate axial capacity to prevent the needle hub from working loose from the syringe during handling and suflicient torque capacity to enable the mating parts of the Luer adapter to form an adequate seal to permit injection.

A further object is to provide a hub for a disposable 3,507,279 Patented Apr. 21, 1970 hypodermic needle which may be used with existing hypodermic syringes and which can be manufactured economically and inexpensively.

These and other objects and advantages are most effectively attained in accordance with the present invention by providing an improved hypodermic needle assembly for use with a hypodermic syringe of the type having a tubular tip extending forwardly from its front end and a retaining collar with internal thread means thereon in a spaced relationship with the tubular tip. The retaining collar and tip are adapted to receive and retain a cannula supporting hub to which a cannula is affixed. The cannula supporting hub of the present invention includes a tubular body portion having a needle at one end and a pair of diametrically opposed flanges extending outwardly from a point proximal the other end. The bottom surface of each flange is beveled from the junction of the body portion and flange to the flange free edge. The top surface of each flange tapers away from the body portion end over a major portion of the arcuate length of the flange to define a partial thread that is complementary to the internal threads of the retaining collar and is adapted to cooperate with the retaining collar thread in securing the needle to a hypodermic syringe and enabling the needle hub to withstand axial loads applied thereto without moving relative to the retaining collar.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a side elevational view of a cannula hub embodying the present invention showing the full circumferential length of each of the flange portions;

FIG. 2 is a view similar to FIG. 1 with the hub rotated approximately about its longitudinal axis;

FIG. 3 is a bottom plan view of the present hub;

FIG. 4 is a top plan view of the present hub;

FIG. 5 is a vertical section partly in elevation, depicting the hub threaded to the supporting collar of an associated syringe;

FIG. 6 is a sectional view taken along reference lines 66 of FIG. 5 in the direction of the arrows; and

FIG. 7 is a fragmentary sectional view taken along reference lines 77 of FIG. 6 in the direction of the arrows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is now made to the drawings and to FIGS. 1 through 4 in particular wherein a hypodermic needle hub 10 in accordance with the present invention is illus trated. The hub may be formed of any suitable plastic material, including polypropylene and polyethylene. The hub 10 includes a tubular body portion 12 having top and bottom ends 14 and 16. A cannula 18- extends longitudinally outwardly from the top end of the body portion and two diametrically opposed flanges 20 and 22 extend radially outwardly from a point proximal to, but spaced apart from the bottom end 16.

The bottom surfaces 24 and 26 of flanges 20 and 22, respectively, are beveled so as to connect the bottom outer edge 28 and 30 of flanges 20 and 22, respectively, with the base 16 of the tubular body portion. This beveled surface serves to guide the flanges into position when the hub is placed on a hypodermic syringe and hence facilitate placement of the hub. The top surfaces 32 and 34 of flanges 20 and 22 taper upwardly over a major portion of their circumferential length. The remaining portions 36 and 38 of flanges 20 and 22 are generally flat, that is, parallel to the bottom end 16 of tubular body portion 12. The angle that the top surface of each flange makes with respect to the bottom 16 of the body portion is approximately 12. The angle of the top surface together with the flat remaining portions 36 and 38 and the inherent resiliency of the materials from which the hub is produced enables the same needle hub to be used with a hypodermic syringe having a number 9 pitch or a number 10 pitch thread disposed about its retaining collar. Flanges 20 and 22 are diametrically opposed and are centered about extensions of a diameter. Flange sides 56 and 58 are parallel to the diameter and the opposed" sides are spaced apart from one another a distance less than the diameter of the hub body portion measured at its bottom end to facilitate attaching the hub to the retaining collar.

Reference is now made to FIGS. through 7 wherein the hypodermic needle hub of the present invention is shown in combination with an associated hypodermic syringe. The syringe 40 includes a barrel portion 42 having a tubular tip 44 aflixed to its forward end. The tubular tip 44 includes a longitudinal bore 46 extending therethrough in communication with the interior of barrel 42. The tip has a conical or tapered exterior profile and it is of such size as to form a sealing engagement with the inner bore 48 of needle hub 10. In this connection, it is to be noted that the inner bore 48 of the needle hub is similarly conical to that of the syringe tip. A retaining collar 50 projects forwardly from the front end of barrel 42 in spaced concentric relationship with twbular tip 44. The retaining collar is spaced apart from the tip a distance suflicient to accommodate the diametrically opposed flange portions 20 and 22 of the needle hub.

Two diametrically opposed helical threads, 52 and 54, extend about the inner surface of retaining collar 50 andact as cams for trictionally engaging the sides 56 and 58 of each flange in a wedging manner. This may best be seen in FIG. 7 wherein it may be observed that engagement between the hub and flange occurs at the top surface of the flange at side 58 and the bottom surface of the flange at side 56 thereby wedging the opposed sides of the flange between threads 52 and 54.

This engagement occurs at both flanges.

The inclined top surfaces of the flanges are substantially complementary to the associated surfaces of threads 52 and 54. Thus, when the needle hub is screwed into the retaining collar of the associated hypodermic syringe, contact is made over the tapered top surface of each flange in addition to the retaining force exerted along sides 56 and 58 of each flange. This increases the area of contact of the hub and retaining collar. Distributing the load over the entire flange as described. above, rather than concentrating the load on the corners of the flanges, as was done with prior art hubs, results in a lower stress or load per unit area to which the hub flanges are subjected. This arrangement permits the use of materials for hubs which have relatively low moduli of elasticity and low strength, since axial load on the hub is distributed over substantially the full circumferential length of the flanges, rather than being concentrated solely at the corners as would be the case with prior art supporting hubs.

Having thus described the invention, what is claimed 1. An improved cannula supporting hub for use with a hypodermic syringe of the type having a retaining collar with two single helical threads starting at diametrically opposed points disposed thereon adapted to receive and retain said supporting hub, said hub comprising: a tubular body portion; a top end of said body portion adapted to secure a needle, and a bottom end of said body portion having a pair of diametrically opposed flanges extending radially outwardly proximal to but spaced apart from the bottom terminal end of said body portion, said flanges each having a top surface, a bottom surface, and a free edge spaced radially outwardly from said body portion, the bottom surface of each of said flanges being beveled upward from the junction of said body portion and flange to the free edge of each flange, and the top surface of each of said flanges including a tapered portion extending circumferential about each flange whereby to define a partial thread adapted to cooperate with said retaining collar thread in securing said hub to said hypodermic syringe.

2. The supporting hub, as set forth in claim 1, wherein each of said diametrically opposed flanges are centered about extensions of a diameter at the bottom of said tubular body portion, the sides of said flanges are each parallel to said diameter, and the spacing between the sides of each flange is less than said diameter.

3. The supporting hub, as set forth in claim 1, wherein the top surface of each of said flanges includes a tapered portion extending upwardly from the bottom end of said hub for a major portion of the circumfen ential length of each flange and a flat portion generally perpendicular to the longitudinal axis of said body portion.

4. The supporting hub, as set forth in claim 3, wherein said hub is formed of a flexible material and the tapered portion of the top surface of each of said flanges defines an angle of approximately 12 with the transverse to the longitudinal axis, of said body portion whereby to enable said hub to be used with hypodermic syringes having number 9 or number 10 pitch threads.

References Cited UNITED STATES PATENTS RICHARD A. GAUDET, Primary Examiner M. F. MAJESTIC, Assistant Examiner 

